1. Technical Field
The present disclosure relates to soy-based rubber composition and its methods of manufacture and use.
2. Background Art
Thermoplastic polymers (TPs), such as thermoplastic polyolefins (TPOs), thermoplastic vulcanizates (TPVs), and thermoplastic elastomers (TPEs), are frequently used plastics in many applications, including automobiles and other vehicles. TPs may be modified with rubber materials so that vehicle components molded from the TPs exhibit performance characteristics such as ductile behavior during impact instead of brittle fracture. Component manufacturers desire to incorporate increased amounts of rubber into TPs. But, the cost of the rubber discourages use of sufficient rubber to achieve desired enhanced performance and processing properties, especially increased elongation properties.
Incorporating rubber materials into TPs often uses paraffinic oils, that is, aliphatic oils without functional groups, to form a separate oil phase in the rubber in order to soften the TPs. The softened TPs are more processable, especially when relatively high molecular weight rubber materials are used, such as ethylene propylene diene terpolymer (EPDM).
TPVs exhibit desirable elastomeric physical properties, relative to TPOs with rubber, because the rubber is firmly connected to the amorphous plastic material. In manufacturing TPVs, any free oil and oil rejected from crystallizing plastic material is reabsorbed into the rubber material and the amorphous plastic material.
But, paraffinic oils are derived from petroleum, a raw material known for its price volatility and ultimately limited renewability. What are needed include more renewable and cost effective materials and associated methods for manufacturing processable TPs having performance properties suitable for vehicular panels.